1 
2 /*
3  * Copyright 2011 Google Inc.
4  *
5  * Use of this source code is governed by a BSD-style license that can be
6  * found in the LICENSE file.
7  */
8 #include "SkLayer.h"
9 #include "SkCanvas.h"
10 
11 //#define DEBUG_DRAW_LAYER_BOUNDS
12 //#define DEBUG_TRACK_NEW_DELETE
13 
14 #ifdef DEBUG_TRACK_NEW_DELETE
15     static int gLayerAllocCount;
16 #endif
17 
18 ///////////////////////////////////////////////////////////////////////////////
19 
SkLayer()20 SkLayer::SkLayer() {
21     fParent = NULL;
22     m_opacity = SK_Scalar1;
23     m_size.set(0, 0);
24     m_position.set(0, 0);
25     m_anchorPoint.set(SK_ScalarHalf, SK_ScalarHalf);
26 
27     fMatrix.reset();
28     fChildrenMatrix.reset();
29     fFlags = 0;
30 
31 #ifdef DEBUG_TRACK_NEW_DELETE
32     gLayerAllocCount += 1;
33     SkDebugf("SkLayer new:    %d\n", gLayerAllocCount);
34 #endif
35 }
36 
SkLayer(const SkLayer & src)37 SkLayer::SkLayer(const SkLayer& src) : INHERITED() {
38     fParent = NULL;
39     m_opacity = src.m_opacity;
40     m_size = src.m_size;
41     m_position = src.m_position;
42     m_anchorPoint = src.m_anchorPoint;
43 
44     fMatrix = src.fMatrix;
45     fChildrenMatrix = src.fChildrenMatrix;
46     fFlags = src.fFlags;
47 
48 #ifdef DEBUG_TRACK_NEW_DELETE
49     gLayerAllocCount += 1;
50     SkDebugf("SkLayer copy:   %d\n", gLayerAllocCount);
51 #endif
52 }
53 
~SkLayer()54 SkLayer::~SkLayer() {
55     this->removeChildren();
56 
57 #ifdef DEBUG_TRACK_NEW_DELETE
58     gLayerAllocCount -= 1;
59     SkDebugf("SkLayer delete: %d\n", gLayerAllocCount);
60 #endif
61 }
62 
63 ///////////////////////////////////////////////////////////////////////////////
64 
isInheritFromRootTransform() const65 bool SkLayer::isInheritFromRootTransform() const {
66     return (fFlags & kInheritFromRootTransform_Flag) != 0;
67 }
68 
setInheritFromRootTransform(bool doInherit)69 void SkLayer::setInheritFromRootTransform(bool doInherit) {
70     if (doInherit) {
71         fFlags |= kInheritFromRootTransform_Flag;
72     } else {
73         fFlags &= ~kInheritFromRootTransform_Flag;
74     }
75 }
76 
setMatrix(const SkMatrix & matrix)77 void SkLayer::setMatrix(const SkMatrix& matrix) {
78     fMatrix = matrix;
79 }
80 
setChildrenMatrix(const SkMatrix & matrix)81 void SkLayer::setChildrenMatrix(const SkMatrix& matrix) {
82     fChildrenMatrix = matrix;
83 }
84 
85 ///////////////////////////////////////////////////////////////////////////////
86 
countChildren() const87 int SkLayer::countChildren() const {
88     return m_children.count();
89 }
90 
getChild(int index) const91 SkLayer* SkLayer::getChild(int index) const {
92     if ((unsigned)index < (unsigned)m_children.count()) {
93         SkASSERT(m_children[index]->fParent == this);
94         return m_children[index];
95     }
96     return NULL;
97 }
98 
addChild(SkLayer * child)99 SkLayer* SkLayer::addChild(SkLayer* child) {
100     SkASSERT(this != child);
101     child->ref();
102     child->detachFromParent();
103     SkASSERT(child->fParent == NULL);
104     child->fParent = this;
105 
106     *m_children.append() = child;
107     return child;
108 }
109 
detachFromParent()110 void SkLayer::detachFromParent() {
111     if (fParent) {
112         int index = fParent->m_children.find(this);
113         SkASSERT(index >= 0);
114         fParent->m_children.remove(index);
115         fParent = NULL;
116         this->unref();  // this call might delete us
117     }
118 }
119 
removeChildren()120 void SkLayer::removeChildren() {
121     int count = m_children.count();
122     for (int i = 0; i < count; i++) {
123         SkLayer* child = m_children[i];
124         SkASSERT(child->fParent == this);
125         child->fParent = NULL;  // in case it has more than one owner
126         child->unref();
127     }
128     m_children.reset();
129 }
130 
getRootLayer() const131 SkLayer* SkLayer::getRootLayer() const {
132     const SkLayer* root = this;
133     while (root->fParent != NULL) {
134         root = root->fParent;
135     }
136     return const_cast<SkLayer*>(root);
137 }
138 
139 ///////////////////////////////////////////////////////////////////////////////
140 
getLocalTransform(SkMatrix * matrix) const141 void SkLayer::getLocalTransform(SkMatrix* matrix) const {
142     matrix->setTranslate(m_position.fX, m_position.fY);
143 
144     SkScalar tx = SkScalarMul(m_anchorPoint.fX, m_size.width());
145     SkScalar ty = SkScalarMul(m_anchorPoint.fY, m_size.height());
146     matrix->preTranslate(tx, ty);
147     matrix->preConcat(this->getMatrix());
148     matrix->preTranslate(-tx, -ty);
149 }
150 
localToGlobal(SkMatrix * matrix) const151 void SkLayer::localToGlobal(SkMatrix* matrix) const {
152     this->getLocalTransform(matrix);
153 
154     if (this->isInheritFromRootTransform()) {
155         matrix->postConcat(this->getRootLayer()->getMatrix());
156         return;
157     }
158 
159     const SkLayer* layer = this;
160     while (layer->fParent != NULL) {
161         layer = layer->fParent;
162 
163         SkMatrix tmp;
164         layer->getLocalTransform(&tmp);
165         tmp.preConcat(layer->getChildrenMatrix());
166         matrix->postConcat(tmp);
167     }
168 }
169 
170 ///////////////////////////////////////////////////////////////////////////////
171 
onDraw(SkCanvas *,SkScalar opacity)172 void SkLayer::onDraw(SkCanvas*, SkScalar opacity) {
173 //    SkDebugf("----- no onDraw for %p\n", this);
174 }
175 
176 #include "SkString.h"
177 
draw(SkCanvas * canvas,SkScalar opacity)178 void SkLayer::draw(SkCanvas* canvas, SkScalar opacity) {
179 #if 0
180     SkString str1, str2;
181  //   this->getMatrix().toDumpString(&str1);
182  //   this->getChildrenMatrix().toDumpString(&str2);
183     SkDebugf("--- drawlayer %p opacity %g size [%g %g] pos [%g %g] matrix %s children %s\n",
184              this, opacity * this->getOpacity(), m_size.width(), m_size.height(),
185              m_position.fX, m_position.fY, str1.c_str(), str2.c_str());
186 #endif
187 
188     opacity = SkScalarMul(opacity, this->getOpacity());
189     if (opacity <= 0) {
190 //        SkDebugf("---- abort drawing %p opacity %g\n", this, opacity);
191         return;
192     }
193 
194     SkAutoCanvasRestore acr(canvas, true);
195 
196     // apply our local transform
197     {
198         SkMatrix tmp;
199         this->getLocalTransform(&tmp);
200         if (this->isInheritFromRootTransform()) {
201             // should we also apply the root's childrenMatrix?
202             canvas->setMatrix(getRootLayer()->getMatrix());
203         }
204         canvas->concat(tmp);
205     }
206 
207     this->onDraw(canvas, opacity);
208 
209 #ifdef DEBUG_DRAW_LAYER_BOUNDS
210     {
211         SkRect r = SkRect::MakeSize(this->getSize());
212         SkPaint p;
213         p.setAntiAlias(true);
214         p.setStyle(SkPaint::kStroke_Style);
215         p.setStrokeWidth(SkIntToScalar(2));
216         p.setColor(0xFFFF44DD);
217         canvas->drawRect(r, p);
218         canvas->drawLine(r.fLeft, r.fTop, r.fRight, r.fBottom, p);
219         canvas->drawLine(r.fLeft, r.fBottom, r.fRight, r.fTop, p);
220     }
221 #endif
222 
223     int count = this->countChildren();
224     if (count > 0) {
225         canvas->concat(this->getChildrenMatrix());
226         for (int i = 0; i < count; i++) {
227             this->getChild(i)->draw(canvas, opacity);
228         }
229     }
230 }
231